Electric switch



July 14, 1925. l 1,545,579

J. BRADLEY ELECTRIC SWITCH Filed Dec. 28, 1925 TOR f//s ATTORNEYS Palmasv July 14, 1925. l

y UNITED STATES y1,545,579 PATENT oFFlcE.

l Josua Bamm; or Bnooxmm, Naw Yoan.

- Enno'rnrc swims.

Application led Illecember 28, 41923. Serial No. 683,133.

Improvement 'i'n Electric Switches, of which the following is aispecification.

' My present invention relates to an velectric switch and more particularly` to that type of switch in which an electric circuit is made vand broken through a liquid contact. In

switches of this type it has been -customary heretofore to employ mercury as the liquid contact member in conjunction withva terminal which is suitably moved into and out of the mercury for making and braking the electric circuit. The movable contact asA heretofore employed is found in practice to accumulate a coating by oxidation or other- Wire, for example by the adhesion of foreign particles thereto sothat sooner or later the connection betweenl the Ymovable contact and the liquid .contact is impaired to such an e'x'- tent as to interfere with the eilicient operation of the switch.. The object of my present invention is the provision, in an electric switch of a movable contact member so constructed that -aportion of the li uid contact member adheres theretowhent e movable a contact member is withdrawn from the liquid contact member in opening a circuit so that when the movable contact member is reinserted into the liquid contact member in again making the circuit there'is a sufiicient quantity of the liquid .contact member carried by the movable contact member, to reunite with thev liquid contact member `in -remaking the vcircuit to cause-the sutitch to operate eiliciently and without attention for an exceedingly long period. In carryingout the inventlon, therefore, I employ a movable contact member which is constructed in any desired Way to provide a plurality of slightl spaced tongues or fingers having intermedilate recesses or grooves for permitting sufiicientv adhesion between the arts of the movable contact member and t e liquid ,contact member to accomblish the purposesdesired. Also incarrying out the invention, particularly 'where mercury is employed as the liquid contact member of the switch, I prefer to use a stem or link to `which the movable contact member is connected and which is made of a material of such a nature that there is substantially no adhesion between the mercury and this member of the switch.

ork, 'have invented an` For this In thevdrawing: v

Fig. lis a transverse section and partial elevation illustrating an electric switch and an apparatus for opera-ting the same made in accordance with my present invention. F.Figa 2 is an enlarged section on line 2 2,

10. p Big. 3 is an enlarged longitudinal section of the stem or link member and the movable contact member associated therewith, and i Fig. 4 is a perspective view of the stem or. link member and also the movable contact member showing these parts in a s eparated relationship.

By reference to the drawing it will be seen that in carrying out myinvention I employ a receptacle v1() made of any suitable mal purpose, I have found that duralumln may be employed to advantage'.

terial and adapted to contain a quantityr of meren? 11 or other similar materia l1qu1d orm adapted to be employed as the liquid contact o a switch for o ning and closing an electric circuit. As il ustrated, I

also refer to employ a suitable liquid cover- 1n orthe mercury, as for example oil as in icated at 12 to prevent themercury from coming into contact with the air and thus conserving the same as far as possible.` 'Ihe receptacle 1() is provided with'a terminal 13 `extending' into the same so as to lie within the mercury contact, while exteriorly of the v p post receptacle the same `comprisesa bindin 1 4. The receptacle may also be ti-ttedgwith a suitable top or cover 15 which is' removable and which may be secured thereto in any' suitable manner. t

The movable contact to which my invention more particularly relates comprises, as illustrated, a pair of contact plates 17, 18. These plates may be riveted together as indicated at 19 and preferably includeexte'nsions 20 and 21'form1n clips by which the movable contact may connected to a stem or plunger as hereinafter described. The contact plates 17 and 18 are so'formed as to have the major portions thereof slightly separated so as to form an intervening relatively narrow space. Also as indicated, the 'extremities of these contact plates are rovided with tongues 17 18 which are slig tly separated from each other so asto leave mtervenin notches. The space between the separat rtions of the contact plates and the notches tween the tongues at the extremities thereof are so formed as to receive and retain a member, a solid contact member havin a plurality of tongues with intermedlate spaces adapted to retain a portion of the liquid contact member therein when withdrawn from the same.

4. In an electric switch, a liquidcontact member, a solid contact member having a plurality of tongues with intermediate Spaces adapted to retain a portion of the liquid, contact member therein when withdrawn from the same, and means for moving the solid contact member into and out of the liquidcontact member to make and break an electric circuit.

5. In an electric switch, a liquid contact member, a solid contact member having a plurality of separated parts each having a plurality of tongues whereby intermediate spaces' are provided for retaining a part of the liquid contact member when withdrawn therefrom.

6. In anv electric switch, a liquid contact member, a solid contact member having a plurality of separated parts each having a plurality of tongues whereby intermediate spaces are provided for retaining a part of the liquid contact member when withdrawn therefrom, and means for moving the solid contact member into and out of the liquid contact .member to make and break an electric circuit. a

7. In an electric switch, a 'liquid contact member, a solid contact member comprising separated plates each having a plurality of tongues at its extremity for providing a space between the plates and slots between the tongues adapted to retain a part ofthe liquid contact member therein when withdrawn from the same.

8. In an electric switch, a liquid contact member, a solid contact member comprising separated plates each having a plurality of tongues at its extremity for providing a space between the plates and slots between the tongues adapted to retain a part of the liquid contact member therein when withdrawn from the same, and means for movmember, a solid contact member, a plunger steml to which the said solidcontact member is removably attached, lmeans for actuating the plunger stem fon moving the solidv contact member into and out of the said liquid contact member, the said'solid contact member comprising separated plates having a space between the same adapted to retain a part of the liquid Contact member therein when withdrawn from the'same.

10. In an electric switch, a liquid contact member, a solid contact member, a plunger stem to which the said solid contact'member is removably attached, means for actuating the plunger stem for moving the solid contact member into and out of the said liquid contact member, the said solid contact member comprising separated plates` each having a plurality of tongues at its extremity providing a space between the plates and slots between the tongues adapted to retain a part of the, liquid contact member therein when Withdrawn from the same.

11. In an electric switch, a liquid contact member, a contact member having a plurality of spaced parts, a plungerstem made of a material on which the liquid contact member does not spread, and means for actuating the plunger stem for moving the contact member into and out of the liquid contact member to make and break an electric circuit.

12. In an electric switch, a mercury contact member, a contact member having a plurality of spaced parts, a plunger stem of duralumin to which the contact member'is removably connected, and means for reciprocating the plunger stem to move the contact member into and out of the mercury contact member.

Signed by me this 22nd day of December,

y.osIAH BRADLEY. 

